<div class="help-items" *ngFor="let item of helpList">
  <ul (click)="executeOpenDetail(item.id)">
    <li>{{item.title}}</li>
    <li [class.open]="index==item.id"></li>
  </ul>
  <div *ngIf="index==item.id">{{item.content}}</div>
</div>
